System and method for applying a bladder release agent between a green tire and a bladder in a tire curing machine

ABSTRACT

A lubricating system indirectly applies a bladder release agent to a green tire and cures the green tire in a tire curing machine. The system includes a deposition device and a curing bladder. The deposition device directly applies bladder release agent on to a deposition bladder. The deposition bladder is inflated within the green tire in order to deposit the bladder release agent on to an inner surface of the green tire. The curing bladder subsequently receives the green tire with bladder release agent deposited therein and cures the green tire.

FIELD OF THE INVENTION

The present invention relates to tire manufacturing and, moreparticularly, to a system and method for a applying a bladder releaseagent to an interior surface of a green tire and then curing the greentire with the bladder release agent between the interior surface of thegreen tire and an inflatable bladder in a tire curing machine.

BACKGROUND OF THE INVENTION

In the manufacture of tires, typically used for automobiles and trucks,a green tire (one which is already formed/built, but not cured) isplaced in an open mold within a conventional tire curing/moldingmachine. The green tire is positioned about a deflated bladder disposedwithin the mold section of the curing machine. Subsequently, the moldsection is closed and sealed, the bladder is inflated against theinterior surface to force the exterior surface of the green tire againstthe heated mold walls whereby the green tire receives a tread pattern.After some period of time, the green tire is cured, the inflatablebladder is deflated, the mold is opened, and the now cured tire ejectedfrom the mold. The inflatable bladder may stick to the interior surfaceof the cured tire after the curing operation and deflation of thebladder. Consequently, a machine operator would manually separate thebladder from the interior surface of the cured tire so that the curedtire could be ejected and a new green tire inserted into the curingmachine. This causes a costly and time consuming delay in the tiremanufacturing process.

To lessen or eliminate this delay, a machine operator may spray acoating of bladder release agent on the interior surface of the greentire and/or the bladder with a paint gun prior to loading the green tirewithin the curing machine and inflating the bladder. While thistechnique may ensure that the bladder separates from the interiorsurface of the cured tire when curing is complete, it may still requireda delay for the machine operator to individually spray each tire and/orbladder before the green tire is loaded into the curing machine.Further, the machine operator must carefully apply the bladder releaseagent to ensure that the bladder release agent completely covers theinterface between the interior surface of the green tire and the bladderso that no part of the bladder sticks to the cured tire. Beside being acostly, time consuming process, which slows the production of tires, itmay also be subject to operator error. This error may occur randomlywith inconsistencies in application of the bladder release agent andsticking of part of the uncoated sections of the tire to the bladder.

Further, excess bladder release agent may accumulate on and contaminatethe mold walls because of the tendency for dirt to cling to the viscousbladder release agent. This contamination may produce inconsistent heattransfer between the bladder and the interior of the green tire leadingto undercured portions of the tire and, ultimately, accumulation ofcostly scrap. Additionally, this contamination may necessitate stoppageof the tire production line to clean the molds. Further, this method maynot be adaptable to modern manufacturing techniques where the entireprocess is conducted by automated machines and/or robots.

A system, apparatus, and/or method of curing a green tire to prevent thesticking of the bladder to the interior of a cured tire, without amanual step by a machine operator may be desirable. It is an object ofthe present invention to provide such a system, apparatus, and methodfor applying a bladder release agent between a green tire and a bladderin a tire curing machine thereby obviating delay/scrap issues ofconventional techniques.

SUMMARY OF THE PRESENT INVENTION

A lubricating system indirectly applies a bladder release agent to agreen tire and cures the green tire in a tire curing machine. The systemincludes a deposition device and a curing bladder. The deposition devicedirectly applies bladder release agent on to a deposition bladder. Thedeposition bladder is inflated within the green tire in order to depositthe bladder release agent on to an inner surface of the green tire. Thecuring bladder subsequently receives the green tire with bladder releaseagent deposited therein and cures the green tire.

According to another aspect of the lubricating system, a tire loaderpositions the green tire over the deposition bladder, removes the greentire from the deposition bladder, and positions the green tire over thecuring bladder.

According to still another aspect of the lubricating system, thedeposition device comprises a “sacrificial” green tire directly sprayedwith bladder release agent.

According to yet another aspect of the lubricating system, thedeposition bladder is the curing bladder and the “sacrificial” greentire is inserted over the curing bladder and the curing bladder isinflated for at least five seconds.

According to still another aspect of the lubricating system, a pre-curebladder deposition machine is disposed along a conveyor system between atire building machine and the curing bladder, the deposition bladderbeing part of the pre-cure bladder deposition machine.

According to yet another aspect of the lubricating system, thedeposition bladder is the curing bladder.

A method indirectly applies bladder release agent to a green tire andcures the green tire. The method includes the steps of: directlyapplying bladder release agent on to a deposition bladder; inflating thedeposition bladder within the green tire in order to deposit the bladderrelease agent on to an inner surface of the green tire; and subsequentlycuring the green tire with bladder release agent deposited therein.

According to another aspect of the method, the directly applying stepfurther includes the steps of: positioning the green tire over thedeposition bladder; indirectly applying bladder release agent to thedeposition bladder; removing the green tire from the deposition bladder;and curing the green tire.

According to still another aspect of the method, the method furtherincludes the step of directly spraying a “sacrificial” green tire withbladder release agent.

According to yet another aspect of the method, the method furtherincludes the step of inflating the deposition bladder within anothergreen tire during curing of the other green tire.

According to still another aspect of the method, the method furtherincludes the step of providing a pre-cure bladder deposition machinedisposed along a conveyor system between a tire building machine and acuring bladder, the deposition bladder being part of the pre-curebladder deposition machine.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example and with reference tothe accompanying drawings, in which:

FIG. 1 is a schematic plan view of a tire curing machine for use withthe present invention;

FIG. 2 is a schematic plan view of a tire loader having eight tireloading paddles of the tire curing machine of FIG. 1;

FIG. 3 is a schematic elevation view, partly in cross section, throughline 3-3 in FIG. 2, showing tire loading paddles of the tire loadergripping a green tire;

FIG. 4 is a schematic elevation view, partly in cross section,illustrating the tire curing machine of FIG. 1, and a green tire on atire loader, prior to being loaded into the tire curing machine;

FIG. 5 is a schematic elevation view, partly in cross section,illustrating the tire curing machine of FIG. 1, with the green tire on atire loader positioned directly above the bladder, just prior to beingloaded into the mold;

FIG. 6 is a schematic elevation view, partly in cross section,illustrating the tire curing machine of FIG. 1, with the green tire on atire loader positioned over/around the bladder before release by thetire loader;

FIG. 7 is a schematic elevation view, partly in cross section,illustrating the tire curing machine of FIG. 1, after a mist of bladderrelease agent has been applied between the interior surface of the greentire and the bladder;

FIG. 8 is a schematic enlarged view of a tire loading paddle of theloading machine incorporating a feed line and nozzle of a conventionallubrication;

FIG. 9 is a schematic enlarged view of the conventional lubricationsystem;

FIG. 10 is a schematic enlarged view of a tire loading paddle of thetire loader incorporating another conventional lubrication system;

FIG. 11 is a schematic elevation view of a tire loading paddle of thetire loader incorporating another conventional lubrication system;

FIG. 12 is a schematic view through line 12-12 of FIG. 11, showing afront view of the tire loading paddle of FIG. 11;

FIG. 13 is a schematic front detail view of an orifice of the nozzle ofthe system of FIG. 11;

FIG. 14 is a schematic view through line 14-14 of FIG. 13, showing aside cross-sectional view of the nozzle of the system of FIG. 11;

FIG. 15 is a schematic perspective view of the tire loading paddle ofFIG. 11, showing the spray pattern of the nozzle of the system;

FIG. 16 is a schematic elevation view, partly in cross section,illustrating an additional pre-spray step of operation of theconventional tire curing machine;

FIG. 17 is a schematic elevation view of a device in accordance with thepresent invention;

FIG. 18 is a schematic elevation view of the device of FIG. 17 under adifferent condition; and

FIG. 19 is a schematic elevation view of the device of FIG. 17 under astill different condition.

DETAILED DESCRIPTION OF EXAMPLES OF THE PRESENT INVENTION

Referring to FIGS. 1 & 4-7, a tire curing machine 10 is shown for curinga green tire 12 within a tire mold 14 having an inflatable bladder 16for pressing the green tire against the inwardly facing surfaces 18, 20of the tire mold 14. A tire loader 22, as shown in FIG. 2, includes aplurality of tire loading paddles 24A, 24B, 24C, 24D, 24E, 24G, 24H(24A-24H) for picking up a green tire 12 from a storage station, such asa platform 15, and loading it into a tire mold 14. A lubricating system26 may mounted on tire loader 22 and have a lubrication delivery section27, as shown in FIG. 9, secured to each of the plurality of tire loadingpaddles or support arms 24A-24H for applying a bladder release agent orlubricant into the enclosed space 25 between the green tire 12 and theinflatable bladder 16, as shown in FIGS. 6 & 7.

As shown in FIGS. 4-7, the tire curing machine 10 has a base support 28onto which is secured the tire mold 14. The tire mold 11 has a bottomsection 30 and a top section 32, shown in its upright, open position. Amechanism 34 for opening and closing the mold 14 is schematicallyillustrated. The mechanism 34 operates by pivoting closed the topsection 32 and lowering it against the bottom section 30, where it issealed in place. Alternatively, the mechanism 34 raises the top section32 away from the bottom section 30, and then pivots the former open to aposition as shown in FIGS. 4-7.

An inflatable bladder 16 having an outwardly facing surface 17 may bemounted within the tire mold 14 and secured to the bottom section 30.The bladder 16 may be inflated with air from a supply (not shown) anddeflated as required. The inflatable bladder 16 may be constructed ofrubber and/or an elastomer.

The tire loader 22 may include an upright support 36 which is secured atits lower end to the base support 28. The upright support 36 may includea movable support structure 38 which moves up and down and pivots abouta rod 39. The tire loading paddles 24A-24H may be secured at their upperend sections 42A,42B,42C,42D,42E,42F,42G,42H (42A-42H) to a support armoperator 40, which in turn may be mounted to the movable supportstructure 38. The upper end sections 42A-42H of the support arms24A-24H, as shown in FIG. 3, may be pivotally mounted to the support armoperator 40 so that the lower end sections44A,44B,44C,44D,44E,44F,44G,44H (44A-44H) of the support arms 24A-24Hmay move radially outward and radially inward toward a centerline 46extending through the tire loader 22. When the lower end sections44A-44H are closest to the centerline 46, the effective diameter of acircle formed about the outwardly facing surface of the lower endsections 44A-44H of the tire loading paddles 24A-24H may be smaller thanthe diameter of the openings 48, 50 formed on either side of the greentire 12 so that the lower end sections 44A-44H may be easily insertedand/or removed from the opening 48 of the green tire 12.

Conversely, when the lower end sections 44A-44H are moved outward fromthe centerline 46, until the effective diameter of a circle formed aboutthe outwardly facing surfaces of the lower end sections 44A-44H of thetire loading paddles 24A-24H is larger than the diameter of the openings48, 50 formed on either side of the green tire 12, the lower endsections 44A-44H then press against the circular surface forming theopening 48 to securely grip the green tire 12 so that the green tire maybe picked up and loaded into the mold 14.

FIG. 8 shows a detailed illustration of a tire loading paddle 24A. Sincethe tire loading paddles 24A-24H may be substantially identical, only adescription of the tire loading paddle 24A is included herein. The tireloading paddle 24A may have a curved, elongated plate section 49A withan inwardly facing curved surface 52A that faces the centerline 46 andan outwardly facing curved surface 54A mounted onto two elongated plates56A, 58A. The upper ends of plates 56A, 58A may form an upper endsection 42A and may be pivotally secured to the support arm operator 40.The lower ends of plates 56A, 58A may be secured in abutting relation toa stop plate 60A which extends substantially perpendicularly outwardfrom the outwardly facing curved surface 54A of the plate section 49A.

During operation, the tire loading paddles 24A-24H may be moved downwardand inserted into the opening 48 of the green tire 12 until the stopplates 60A-60H are abutted against the side wall of the green tire 12.Then, the upper end sections 42A-42H of the loading arms 12A-12H may bepivoted outward and away from the centerline 46, until the lower endsections 44A-44H of the elongated plate sections 49A-49H, such as theend sections 44A,44B,44C, 44G, shown in FIG. 3, frictionally engage thesurface forming the opening 48 of the green tire 12 to securely grip thegreen tire and enable the green tire to be raised or lowered as it isloaded or removed from the mold 14.

A lubricating system 26 may include a fluid dispenser 62, as shown inFIG. 9. The fluid dispenser 62 may include an enclosure 65 containingeight separate pump units 68,70,72, 74,76,78,80,82 (68-82) stacked onone another. The enclosure 65, shown in FIG. 3, may be mounted on themovable support structure 38 of tire loader 22. However, the fluiddispenser 62 may be mounted at some other location on or adjacent thetire curing machine 10. The fluid dispenser 62 may further include areservoir 64 of liquid bladder release agent and have two air pulsegenerators 66A, 66B actuated by a solenoid valve 83 drawing air throughan air filter 85. The air pulse generators 66A, 66B may determine thestroke rate of the pump units 68-82. Air may be added immediatelydownstream of the pump units 68-82. The resultant output stream of airmay be added to the liquid bladder release agent from the reservoir 64to atomize the bladder release agent being pumped from the eight pumpunits 68-82. Eight injector-liquid adjustment knobs 84, one for eachpump unit 68-82, may independently adjust the liquid output and airmetering screws 86 may control the flow of air. Flexible capillary tubes88 may be connected at one end to the individual pump units 68-82 and atthe other end to the individual couplings 90, which in turn may besecured to each of the tire loading paddles 24A-24H. For each of thetire loading paddles 24A-24H, a delivery tube 92 may be attached at oneend to the couplings 90 and at the other end to nozzles 94. The nozzles94 may be individually mounted in a throughhole which extends throughthe lower ends 44A-44H of the plate sections 48A-48H of the tire loadingpaddles 24A-24H, such as adjacent the intersection of the plate section48A with the stop plate 60A. The nozzles 94 may be positioned so thatthe spray of mold release agent is emitted at a downward directed anglewith respect to the inner surface of each plate section 48A-48H.

In operation, the movable support structure 38 may initially movedownward along the rod 39 with the tire loading paddles 24A-24H in acontracted position so that the lower ends 44A-44H may enter the opening48 of the green tire 12 resting on the surface 15 until the stop plates60A-60H engage the upward facing side surface of the green tire 12.Then, the upper end sections 42A-42H may be pivoted outward causing theradial distance of the tire loading paddles 24A-24H from the centerline46 to increase, which thereby causes the lower end sections 44A-44H tofrictionally engage the surface of the opening 48 of the green tire 12.Next, the movable support structure 38 may return upward along the rod39 into the position shown in FIG. 4. The support structure 38 may thenrotate about the rod 39 so that the green tire 12 is positioned abovethe bottom section 30 of the tire mold 14 with the lower opening 50through the green tire 12 directly above the collapsed bladder 16. Next,the support structure 38 may be begin to move downward so that the stopplates press against the upward facing wall of the green tire 12 andseat the bead formed about the tire opening 50 against the bottomsection 30 of the tire mold 14. Simultaneously with, or shortly before,the previous step, the lubricating system 26 may be activated and a mistof mold or bladder release agent sprayed from each nozzle 94 against theouter facing surface 17 of the collapsed bladder 16.

The confined space 25 between the inner surface of the green tire 12 andthe outer surface 17 of bladder 16 may be filled with the mist of moldor bladder release agent. As the top section 32 begins to rotate andclose against the bottom section 30 of the tire mold 14, the tireloading paddles 24A-24H may begin to retract towards the centerline 46and move upward and away from the inner surface 18 of the bottom moldsection 30. The support structure 38 may continue to move upward untilthe tire loading paddles 24A-24H are free from the opening 48 and abovethe bladder 16 so that the top section 32 of the tire mold 14 may closeand seal the tire mold 14 for a subsequent curing step.

The nozzles 94 may be directed towards the collapsed bladder 16 so thatthe spray effectively covers the entire surface 17 of the bladder.However, the spray may be directed away from the bladder 16 so that thebladder release agent has more of a tendency to fill the enclosed space25 between the bladder 16 and the inner surface of the green tire 12.The bladder release agent may be sprayed after the green tire 12 isplaced on/over the bladder 16. This may reduce the possibility of thebladder release agent being able to escape from the enclosed space 25between the bladder 16 and the interior surface of the green tire 12 andonto the interior surface of the tire mold 14 which may contaminate thetire mold and require more frequent cleaning. After the top section 32of the tire mold 14 is secured and sealed onto the bottom section 30 ofthe tire mold 14, the bladder 16 may be inflated to force the green tire12 against the interior mold walls 18, 20. After a specified cure time,the bladder 16 may be deflated and the tire mold 14 may be opened.Finally, the cured tire may be ejected and the process may begin againwith another green tire 14.

Referring to FIG. 10, two nozzles 94 may be mounted in throughholeswhich extend through the lower end 44A of plate section 48A of the tireloading paddle 24A. While only the tire loading paddle 24A isillustrated, two nozzles 94 may be mounted in throughholes which extendthrough two or more, or all of the lower ends 44A-44H of the platesections 48A-48H of the tire loading paddles 24A-24H to more evenlydistribute the bladder release agent in the enclosed space 25 betweenthe bladder 16 and the green tire 12. Each of the throughholes may bedisposed between the longitudinal edges of the plate sections 48A-48Hand the sides of the stop plates 60A-60H. The nozzles 94 may bepositioned in the manner described so that the spray is emitted at adownward directed angle with respect to the inner surface of the platesections 48A-48H.

This conventional lubricating system 26 may be essentially identical tothat shown in FIG. 9 up to the flexible capillary tubes 88, which may beconnected at one end to the individual pump units 68-82, as shown inFIG. 9. However, the other end of capillary tubes 88 may be connected toa coupling 100, which in turn may be secured to the tire loading paddles24A-24H. Two delivery tubes 102, 104 may be each attached at one end tothe coupling 90 and at the other end to a nozzle 94. The nozzles 94 maybe secured in throughholes which extend through the plate sections48A-48H so that the spray of bladder release agent is emitted aspreviously discussed.

Referring to FIGS. 11-15, a nozzle 110 may be a divergent spray conenozzle. Since all of the nozzle and lubricating system arrangements, onemounted on each of the tire loading paddles 24A-24H, are substantiallyidentical, only a description of the arrangement of the tire loadingpaddle 24A is included herein. However, all or some of the nozzles 94may be replaced with the nozzle(s) 110. The nozzle 110 may have a closedoutlet end 112 with an orifice 114 which extends through a front wall116 to a bore 118 which opens at a rear inlet end 120. The rear inletend 120 may be threaded for attachment to a pressure valve 122, asdescribed below.

A cylindrical collar 124 may be disposed intermediate the inlet andoutlet ends 120, 112. The nozzle 110 may be mounted to the lower end 44Aof the plate section 49A of tire loading paddle 24A by insertion of theoutlet end 112 into a throughbore 126 of a clamp collar 128 mounted ontothe outwardly facing curved surface 54A so that the outlet end 112 ofthe nozzle 110 projects outward from an opening 130 in the lower end 44Aof the plate section 49A. Note that the opening 130 may be disposed toone side of a longitudinal axis 134, see FIG. 12, through the tireloading paddle 44A. The collar 124 may abut the clamp collar 128 and besecured therein by a means, such as a set screw (not shown).

Referring to FIGS. 13 & 14, the orifice 114 of the nozzle 110 may behave a flat, narrow slot which angles along the sidewalls 136 from aninner opening 138 to an outer opening 140 such that the inner opening issmaller than the outer opening. An angle b from the inner opening 138 tothe outer opening 140 may be between about 80° to about 120°. The flatinterior upper and lower walls 142A, 142B of the orifice 114 may beparallel and extend from the inner opening 138 to the outer opening 140to form an angle c with respect to a first plane 144 through the nozzle110, which may be between about 35° and about 55°, and specificallyabout 45°.

As shown in FIGS. 11 & 12, the nozzle 110 may be mounted to the tireloading paddle 24A so that the first plane 144 through the nozzle 110 isdisposed substantially perpendicular to the inwardly facing surface 52Aof the tire loading paddle 24A. Further, the nozzle 110 may be locatedto one side of the axis 134 through the center of the tire loadingpaddle 24A so that a second plane 145 through the center of the nozzle110, which is perpendicular to the first plane 144 of the nozzle 110(see FIG. 13), may be disposed at an angle d of about 10° to about 50°,or about 25° to about 35°, or about 30° with respect to the axis 134.The spray cone 150 emitted from the orifice 114 may be directed downwardacross the axis 134, as shown in FIG. 12, and toward the centerline 46through the tire loader 24 a, as shown in FIG. 11.

The lubricating system of FIG. 16, which includes the nozzle 110 shownin FIGS. 11-15, may be essentially identical to the lubricating system26 shown in FIG. 9, up to the flexible capillary tubes 88. While theflexible capillary tubes 88 are shown connected to individual pump units68-82 in FIG. 8, in FIGS. 11, 15 & 16, the other end of the capillarytubes 88 may be connected to one end of a coupler 146. The opposite endof the coupler 146 may be connected to the pressure valve 122.

Due to the shape and orientation of the orifice 114 of the nozzle 110, aspray of bladder release agent may exit the orifice 114 in a relativelyflat, divergent spray cone 150 and be directed downward and toward thecenterline 46 of the tire loader 22. Additionally, the orientation andstructure of the nozzle 110, as discussed above, may cause the spraycone 150 of bladder release agent to exit the orifice 114 and cross thelongitudinal axis 134. As illustrated in FIGS. 11, 12 & 15, theorientation and structure of the orifice 114 combined with the effect ofthe pressure on the upper surface 152 of the spray cone 150 being higherthan the pressure on the undersurface 154 of the spray cone 150 and theeffect of gravity creates a “curling effect” of the spray pattern 151forming the spray cone 150. That is, the spray cone 150 of bladderrelease agent from the nozzle 110 may be curled downward and toward oneside of the lower section 49A of the tire loading paddle 24A.

At the same time, the spray pattern may have a tendency to swirl in theclockwise direction because of the orientation and structure of theorifice 114 of the nozzle 110. This spray pattern 151, when emitted fromeach nozzle 110 mounted to the lower section 49A-49H of the loadingpaddles 24A-24H, may distribute the bladder release agent onto both thebladder 16 and the interior surface of the green tire 12 when sprayed inthe confined space 25 therebetween. The swirling, curled spray pattern151 emitted from each of the nozzles 110 may also pre-spray the innersurface of the green tire 12, as discussed below.

The nozzle 110 may also be self-cleaning. The nozzle 110 may be mountedso that, as the tire loading paddles 24A-24H are being withdrawn afterthe bladder 16 has begun to inflate, the rubbing of the inflatablebladder against the opening 140 of the orifice 114 may clean the opening140 from residual bladder release agent.

Referring to FIG. 16, the tire curing machine 10 may also use apre-spray step in its cycle of operation. The movable support structure38 may initially move downward along the rod 39, as shown and describedabove, with the tire loading paddles 24A-24H in a contracted position sothat the lower ends 44A-44H of the tire loading paddles 24A-24H mayenter the opening 48 of the green tire 12 resting on the surface 15, asshown in FIG. 4, until the stop plates 60A-60H engage the upward facingside surface of the green tire 12. Then, the upper end sections 42A-42Hmay be pivoted outward causing the radial distance of the tire loadingpaddles 24A-24H from the centerline 46 to increase, which may furthercause the lower end sections 44A-44H to frictionally engage the surfaceof the opening 48 of the green tire 12. The movable support structure 38may subsequently return upward along the rod 39 into the position shownin FIG. 4. The support structure 38 may then rotate about the rod 39 sothat green tire 12 is positioned above the bottom section 30 of the tiremold 14 with the lower opening 50 through the green tire 12 directlyabove the collapsed bladder 16. The bladder release agent may then bepre-sprayed onto the inner surface of green tire 12, as shown in FIG.16.

The curling of the spray, as discussed above, may cover the lowerinterior half and the lower bead about the opening 50 of the green tire12. During the pre-spraying step, the spray of bladder release agent maynot enter the tire mold 14 because of heated air (e.g., about 350° F.)flowing upward from the tire mold. Next, the support structure 38 maymove downward so that the stop plates 60A-60H press against the upwardfacing wall of the green tire 12 and seat the bead formed about the tireopening 50 against the bottom section 30 of the tire mold 14.Simultaneously with this step, the lubricating system 26 may beactivated and a mist of bladder release agent may be sprayed from eachnozzle 110 against the outer facing surface 17 of the collapsed bladder16.

The space 25 may be confined between the inner surface of the green tire12 and the outer surface 17 of the bladder 16 and may be filled with themist of bladder release agent. The nozzles 110 may also begin sprayingthe bladder release agent as the nozzles pass the bladder 16 during thedownward movement of the support structure 38 towards the tire mold 14.After the top section 32 of tire mold 14 begins to rotate and closeagainst the bottom section 30 of tire mold, the tire loading paddles24A-24H may retract towards the centerline 46 and move upward and awayfrom the inner surface 18 of the bottom mold section 30. The supportstructure 38 may continue to move upward until the tire loading paddles24A-24H are free from the opening 48 and above the bladder 16, so thatthe top section 32 of the tire mold 14 may close and seal the tire moldfor the curing process.

A system 200 and method 200 in accordance with the present invention maylimit the amount of excessive release agent 210 on a green tire 201, butalso deposit the release agent where it is needed in the green tire forreleasing the green tire adequately from the deflated bladder 16. Thesystem/method 200 may utilize an indirect technique for applying therelease agent 210 to the green tire 201 (FIGS. 17-19). This indirecttechnique 200 may allow enhanced control of the amount/quantity ofdeposited release agent 210 and its location on a surface of the greentire 201. As described above, conventional practices utilize a directapplication of the release agent (e.g., spraying) to the inside surfaceof an un-vulcanized/green tire 201.

The indirect transfer technique 200 may coat the inside of the greentire 201 with release agent 210 without having to directly spray anysurface of the green tire. The indirect technique 200 thus mayeliminate/mitigate the issue post cure cracks forming in the innerliner.The cracks may be created by the directly sprayed on release agentaccumulated at the strip edges of the innerliner and in between thestrips causing the strips to not cure to each other. This indirecttechnique 200 was evidenced by a control area on the inside of severalgreen tires that cured properly, but was not sprayed and had nopost-cure cracks. This led to the conclusion that enough release agent210 was transferred from the green tire 201 to the bladder 205 in theprevious cure cycle.

The indirect technique 200 may use a “sacrificial” green tire 201. Theinside of this sacrificial green tire 201 may be directly sprayed withrelease agent 210 (FIG. 17). The sacrificial green tire 201 may then beinserted into a release deposition machine 203 and the bladder 205 maybe inflated for a few seconds (FIG. 18). Thus, the green tire 12 is notcured, but used to transfer the release agent 210 from the sprayed greentire 205 to the curing bladder 16 in the curing machine 10. Thisdeposition of release agent 210 may thereby eliminate the directspraying of production tires 12. Depending on the type/size of greentire 201, this indirect technique 200 may be repeated every 5 to 20 curecycles.

The indirect technique 200 may utilize a pre-cure bladder depositionmachine 203 disposed along a conveyor system (not shown) between a tirebuilding machine and the curing machine 10. To reduce cure cycle time,this technique 200 is not practiced close to the curing machine 10itself. An inflatable depositing/deposition bladder 205 may be directlysprayed, placed inside the green tire 201, and inflated. Release agent210 may thereby be transferred from the deposition bladder 205 to theinside of the green tire 201 (FIGS. 17-19). This bladder depositionmachine 203 may replace a conventional direct spray machine 22.

In addition to the advantages discussed above, the system 200 and method200 of the present invention more effectively and completely coat theinner surface of the green tire 201 during the curing process. Inaccordance with the present invention, a system 200 and method 200applies a bladder release agent 210 between a green tire 201 and abladder 16 in a tire curing machine 10 thereby obviating the issues andlimitations of conventional systems. According to the present invention,a mist of bladder release agent 210 may be placed onto a pre-bladder 205so that the pre-bladder may inflate and coat the inner surface of thegreen tire 201 with an amount of bladder release agent sufficient toallow release of the cured tire from the tire mold 14 after curing, butnot excessive enough to leave significant amounts of bladder releaseagent 210 on the tire mold 14.

While the invention has been described in combination with various otherfeatures, it will be evident that many alternatives, modifications, andvariations are apparent to those skilled in the art in light of theforegoing teachings. Accordingly, the present invention is intended toembrace all such alternatives, modifications, and variations as fallwithin the spirit and scope of the appended claims below.

What is claimed:
 1. A lubricating system for indirectly applying bladderrelease agent to a green tire and curing the green tire in a tire curingmachine, the system comprising: a deposition device for directlyapplying bladder release agent on to a deposition bladder, thedeposition bladder being inflated within the green tire in order todeposit the bladder release agent on to an inner surface of the greentire; and a curing bladder for subsequently receiving the green tirewith bladder release agent deposited therein and curing the green tire.2. The lubricating system as set forth in claim 1 further including atire loader for positioning the green tire over the deposition bladder,removing the green tire from the deposition bladder, and positioning thegreen tire over the curing bladder.
 3. The lubricating system as setforth in claim 1 wherein the deposition device comprises a “sacrificial”green tire directly sprayed with bladder release agent.
 4. Thelubricating system as set forth in claim 3 wherein the depositionbladder is the curing bladder and the “sacrificial” green tire isinserted over the curing bladder and the curing bladder is inflated forat least five seconds.
 5. The lubricating system as set forth in claim 1further including a pre-cure bladder deposition machine disposed along aconveyor system between a tire building machine and the curing bladder,the deposition bladder being part of the pre-cure bladder depositionmachine.
 6. The lubricating system as set forth in claim 1 wherein thedeposition bladder is the curing bladder.
 7. A method for indirectlyapplying bladder release agent to a green tire and curing the greentire, the method comprising the steps of: directly applying bladderrelease agent on to a deposition bladder; inflating the depositionbladder within the green tire in order to deposit the bladder releaseagent on to an inner surface of the green tire; and subsequently curingthe green tire with bladder release agent deposited therein.
 8. Themethod as set forth in claim 7 wherein the directly applying stepfurther includes the steps of: positioning the green tire over thedeposition bladder; indirectly applying bladder release agent to thedeposition bladder; removing the green tire from the deposition bladder;and curing the green tire.
 9. The method as set forth in claim 7 furtherincluding the step of directly spraying a “sacrificial” green tire withbladder release agent.
 10. The method as set forth in claim 7 furtherincluding the step of inflating the deposition bladder within anothergreen tire during curing of the other green tire.
 11. The method as setforth in claim 7 further including the step of providing a pre-curebladder deposition machine disposed along a conveyor system between atire building machine and a curing bladder, the deposition bladder beingpart of the pre-cure bladder deposition machine.